Lambert-Eaton Myasthenic Syndrome Recurrence Induced by Pembrolizumab in a Patient with Non-small-cell Lung Cancer

Abstract

A 73-year-old woman in complete remission from localized small-cell lung cancer associated with Lambert-Eaton myasthenic syndrome (LEMS) 22 years earlier was referred to our hospital and diagnosed with non-small-cell lung cancer. After three courses of pembrolizumab, an immune checkpoint inhibitor, the patient complained of muscle weakness, fatigue, ptosis, and dysarthria. The anti-voltage-gated calcium channel antibody level was elevated, and waxing was observed on a high-frequency repetitive stimulation test using an electromyogram. We diagnosed her with recurrence of LEMS as an immune-related adverse event (irAE) induced by pembrolizumab. After intravenous immunoglobulin therapy, the patient's symptoms improved, and she was discharged.

Durvalumab for Extensive-Stage of Small-Cell Lung Cancer With Lambert-Eaton Myasthenic Syndrome

“…To our knowledge, there were only four malignant cases who had preexisting LEMS but had Durvalumab for Lambert-Eaton Syndrome J Med Cases. 2023;14(2):71-75 been treated by ICIs [7][8][9][10]. These rare cases suggest that ICI is a possible treatment option for cancer patients with LEMS.…”

“…In our case, combined immunochemotherapy did not exacerbate the preexisting LEMS. To our knowledge, there were only four malignant cases who had preexisting LEMS but had been treated by ICIs [ 7 - 10 ]. These rare cases suggest that ICI is a possible treatment option for cancer patients with LEMS.…”

“…In this case, LEMS did not deteriorate by 1.5-year administration of avelumab, which was discontinued because of imAEs of hypothyroidism and drug-induced pneumonitis [ 9 ]. The Japanese case by Takigawa et al [ 7 ] presented a 73-year-old woman who maintained complete remission from localized stage of SCLC associated with LEMS 22 years earlier. Her LEMS recurred by only four courses of pembrolizumab with carboplatin and nab-paclitaxel for c-stage IIIB of pulmonary squamous cell carcinoma.…”

What Is in the Neuromuscular Junction Literature?

“…Takigawa et al 28 reported an interesting single case of LEMS reoccurrence in a 73-year-old woman treated with pembrolizumab. She had limited-stage SCLC with LEMS 22 years earlier and had been in remission after chemoradiation.…”

“…There were several other cases of LEMS with renal cell CA and SCLC in patients receiving ipilimumab, nivolumab, and pembrolizumab, but the ROR was 5-7, and the authors did not consider it to be significantly disproportional. 27 Takigawa et al 28 reported an interesting single case of LEMS reoccurrence in a 73-yearold woman treated with pembrolizumab. She had limited-stage SCLC with LEMS 22 years earlier and had been in remission after chemoradiation.…”